//
//  KVOViewController.m
//  GCD
//
//  Created by fangyuan ding on 2020/8/6.
//  Copyright © 2020 fangyuan ding. All rights reserved.
//

#import "KVOViewController.h"

@interface KVOViewController ()

@end

@implementation KVOViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
}
//KVO
- (void)setNow:(NSDate *)aDate{
    [self willChangeValueForKey:@"now"];
    [super setValue:aDate forKey:@"now"];
    [self didChangeValueForKey:@"now"];
}

@end
